Friday, May 16, 2008

Pictures taken from Der Spiegel (From top-down, trepanated skulls showing techniques: I, II and III, respectively). Click up (title, to see article and more photos from Der Spiegel).

The anthropologists Valerie Andrushko(Conn/State-University/New Haven) and John Verano(Tulane University/N.Orleans), published in the AJPA, the results of a study carried out in 411 individuals (400 years b.C-1400 years a.C), coming from 11 prehispanic cemeteries located in and around Cuzco (southern highlands of Peru), in those that 66 individuals (16%), exhibit cranial trepanations (removal of bony disks), with the aim of reducing the intracranial pressure. Some individuals exhibit but of one trepanation (total = 109 observed perforations). Some few skulls have 4 and 7 simultaneous perforations. But of 90% of having operated survived (they present new bone, appropriately covered) and took a normal life. They registered lower infection rates and only 4.5%, exhibited wound inflammations. Vegetable principles were used to disinfect wounds (saponine, cinamonic acid, tannins).

It was easy to distinguish 3 techniques: I) circle cuts with scraping with and without bevel, made layer after layer (hole drilled), predominant method, highly successful with survival of up to 83%, rate that ascends with the time for improvements in the technique. The surgeons avoided certain areas of the skull - leaving alone bony bridges, extirpated only at the end -for not damaging the meninges and large vein sinuses II) rectangular piece, of right cuts. A single skull presents rectangular hole of 3.98 x3, 90 cm. The patient died before the wound healed III) round cuts with bony graft at the end of the treatment. A rude technique, practiced in acutely affected patients. In these cases the total piece of the fractured skull was extracted, being scraped the edges until smoothing them. According to the researchers the surgeons used stone blades: obsidian and flint and carcass of animals. In 44% of those affected, the causes of the trephination were left cranial traumas caused with overwhelming objects, to effects of tribal wars. Were also object of trepanations, affections like mastoiditis, migraine and sickness.